Various devices are known for trimming thin-walled articles from sheets of thermoformed plastic material. The trimming or severing of such articles from a continuous sheet of thermoformable plastic and/or foam material has long been known in the art. Additionally, sheet guides and mechanical treadles are known for moving the sheet and articles for intermittent severing between coacting punches and dies of a trim press.
U.S. Pat. No. 4,173,161 discloses a mechanical trim press that includes a mechanical treadle having feed fingers mounted on the treadle. The feed fingers comprise a mechanical linkage that interacts with projecting integral tabs formed in the sheet to advance the sheet to a die in step-by-step movement that is mechanically synchronized with the stroke of the punch. The treadle also includes opposed pairs of vertical guide strips between each article. Each guide strip is carried by a spacer that is mounted onto a cross frame member of the treadle. Opposed pairs of guide strips, provided between each adjacent pair of formed articles in the sheet, are spaced apart slightly from each other by a distance slightly greater than the thickness of the sheet passing therebetween. However, such close spacing coupled with the use of guide strips between every adjacent pair of articles results in increased frictional forces which tends to result in mis-feeding and jamming of the treadle, particularly when running the treadle at relatively high product feed rates.